JVC AV-21F9 Service Manual page 14

AV-21F9
Measuring
Item
instrument
Adjustment Remote
of BLACK control unit
OFFSET-I
(SECAM)
REMOTE CONTROL UNIT
BLACK &
WHITE OFF
1
BLACK &
WHITE ON
4
R-Y ( )
7
R-Y ( )
Adjustment Signal
of BLACK generator
OFFSET-II
(SECAM) Oscillo-
scope
Remote
control
unit
[R-Y]
(a)
[B-Y]
(c)
20
Test point Adjustment part
7. BLACK OFFSET
(R-Y)
(B-Y)
2 3
5 6
B-Y ( )
8 9
B-Y ( )
35 PIN (R-Y)
36 PIN (B-Y)
IC 201 on
MAIN PWB 7. BLACK OFFSET
(R-Y)
(B-Y)
Flat Flat
(b)
Flat
Flat
(d)
[Method of adjustment without measuring instrument]
1. Receive a SECAM broadcast.
2. Select 2. V/C from the SERVICE MENU.
3. Select 7. BLACK OFFSET with the MENU a key.
4. Set the initial setting value for BLACK OFFSET (R-Y) and (B-
Y) with 4 and 7 or 6 and 9 keys on the remote control unit.
5. If the picture is not the best with the initial setting value, make
fine adjustment until you get the best picture.
6. Press the DISPLAY key twice to return to the normal screen.
[Method of adjustment using measuring instrument]
1. Receive a SECAM COLOUR bar signal (full field colour bar
75% white).
2. Select 2. V/C from the SERVICE MENU.
3. Select 7. BLACK OFFSET with the a key.
4. Connect the oscilloscope between pin 35 of IC 201 and TP-E.
5. By using 4 and 7 keys on the remote control unit, adjust the
BLACK OFFSET (R-Y) so that the waveform changes from
(a) to (b) as shown in the figure.
6. Connect the oscilloscope between pin 36 of IC 201 and TP-E.
7. By using 6 and 9 keys on the remote control unit, adjust the
BLACK OFFSET (B-Y) so that the waveform changes from
(c) to (d) as shown in the figure.
8. If the picture is not the best with the adjusted picture, make
fine adjustment until you get the best picture.
9. Press the DISPLAY key twice to return to the normal screen.
No. 56037
Description